Common dog violet’s beautiful flowers adorn fertile forests in southern and central Finland from the end of spring and the beginning of summer. A chilly early spring can mean that pollinators do not visit during the flowering time, so to be on the safe side the species grows self-pollinating flowers at the end of the summer that remain unopened. viola riviniana is a PERENNIAL growing to 0.2 m (0ft 8in). It is hardy to zone (UK) 5. It is in flower from April to June, and the seeds ripen from May to July. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees, Lepidoptera (Moths & Butterflies). The plant is self-fertile. It is noted for attracting wildlife. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: acid and neutral soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil. How to get rid of: Wild violets can be removed by hand, especially if you regularly inspect your lawn to control the plant before it spreads. But sometimes this weed calls for the use of chemical herbicides for complete eradication.